Various types of agricultural implements have been developed that can be linked via an implement tongue assembly to a tractor hitch or other type of tow vehicle to facilitate different tasks including, for example, seeding, fertilizing and tilling. Hereinafter, unless indicated otherwise, the background of the invention and the present invention will be described in the context of an exemplary planting implement.
An important fact in accessing the value of a planting implement is how quickly the implement can accomplish the task of the implement. The task speed of the implement can be increased by reducing the number passes required to perform the implement's task for a field. Certain known planting implements are configured to expand to operating field widths of 40-feet or more. Unfortunately, such expansive widths cannot be tolerated during planter transportation, storage, and egress of the implements to and from many agricultural fields. In particular, many farmers use commercial roadways to transport their planting implements to and from the fields, and essentially all roadways are not designed to accommodate expansive planting implements. The industry has developed planting implements that are operable to fold to and from a retracted configuration between transport and intended use.
One certain folding-type planting implement includes a single implement tool bar centrally mounted for pivotal movement on a wheel supported carrier platform where the single arm is pivotable about the mount so that half of the bar extends over the tongue assembly and is a supportable thereby and the other half of the bar extends away from the tractor behind the chassis. The tongue assembly has to be long enough to accommodate the implement bar length plus some clearance so as to allow a tractor linked to the tongue assembly to turn left and right. For example, where the planting implement operating width is 40-feet, the tongue assembly generally has to be greater than 20-feet long.
To ensure that planted along the entire edge of a field, a farmer typically starts seeding the field by first traveling around the edge of the field with a seeding implement at lease once and often two or more times along adjacent consecutively smaller paths prior to traveling in parallel rows through field. These field edge paths are generally referred to in the industry as headland passes. Performing one or more headland passes about a field edge prior to performing parallel passes provides a space for turning the tractor an implement around between parallel passes while still covering the entire space along the field edge. However, headland passes include driving over field sections that have already been seeded, crushing the seeds or growing plants that pass over and reducing overall field production. As known in the industry, farms routinely attempt to reduce the number of headland passes required in a field.
The number of headland passes required to facilitate field coverage is related to the turning radius of a tractor and planter implement combination and the combination turning radius is directly related to the length of the tongue assembly coupling the planting implement with the tractor. Recognizing that a short tongue during planting implement operation reduces the number of headland passes and increases efficiency, and a long tongue is desirable to accommodate pivotal and scissors type implement configurations, the industry has developed telescoping tongue assemblys driven by a hydraulic cylinder to extend and accommodate implement transport, and to retract and provide a minimal turning radius during operation.
Typically, planting implements do not come equipped with their own power units. Most farmers employ many different implements, and a separate power unit for each implement would be too costly. Instead, tractors are typically constructed with power capacities sufficient to transport an implement as well as provide power to operate the implement. In particular, a tractor in tow of a planting implement would provide hydraulic fluid to power any hydraulic cylinders required to rotate on the implement between transport and functional positions, to raise and lower support wheels, to raise and lower an implement tool bar, to extend and retreat the telescopic tongue assembly and to control the hydraulic locking assemblies. In addition, the tractor would also provide electrical power to the hydraulic valves (e.g., solenoid valves), any blower mechanisms for product conveyance to the row metering units and to any other devices requiring electrical power (e.g., tail lights, sensors, etc.).
To provide power to the planting implement, a tractor typically comes equipped with one or, in most cases, a plurality of power or power source ports that are positioned proximate a hitch receiving assembly of the tow vehicle, and the planting implement is equipped with one or more power receiving ports. Power cables are then provided to link associated ports (i.e., hydraulic to hydraulic, electrical to electrical, etc.) together. Generally, the planting implement pivots about the hitch receiver assembly with respect to the tractor and therefore the power cables are constructed to flex and accommodate a degree of pivoting consistent with a minimum tractor turning radius.
As with most assemblies that include flexible lines, e.g., hydraulic hoses, electrical harnesses, pneumatic lines, power cables, etc., the power cables of the planting implement need to be protected from damage. Otherwise, a severed hydraulic fluid line can prevent the planting implement from being rotated to a suitable position for transportation along most roadways. Protecting the power cables is particularly difficult with telescoping tongue assemblies.
U.S. Pat. No. 6,561,535 discloses an agricultural implement employing a sheath member mounted to the tongue assembly to receive power cables from the tractor. The sheath member defines a passageway that restricts bending in the power cables to a single plane. However, when the toolbar planter was folded into and out of transport, the hoses drop down and drag on the toolbar deck. This undesired wear and tear on the hoses increases a potential for failure over time.
There is thus a need for a constraint assembly that reduces wear and tear on the flexible lines associated with operation of the an agricultural implement, and yet positions the flexible lines correctly during telescopic movement of the hitch assembly and/or pivoting/rotating movement of the tool bar assembly between transport and operation of the agricultural implement.